Apparatus for treating gases



Dec. 17, 1935. A. B. RAY 7 Re. 19,791

APPARATUS FOR TREATING GASES Original Filed Feb. '7, 1928 '1 ATTORNEYS.

Reissued Dec. 17, 19 35 j 1 Re.

mana'rus FOR TREATING GASES Arthur B. Ray, Bayside, N. Y., assignor toNany, Inc., a corporation 'tional Carbon Compa New York Original No.1,820,030, dated All!! 25, 1931,

Serial No. 252,654, February 7,1928.

Application for reissue August 12, 193$,Serlal No.

This invention relates to apparatus -for treatin gases to removesubstances therefrom.

The substances to be removed are usually in a gaseous and vapor state,and mixed with the gas 4 Claims. (01. 1am) to be treated. Incertaininstances substances may. be removed from gases and recoveredbecause of their valuable nature, such as solvents 1 used in industrialprocesses which va rize in air; and in other instances substances areremoved from gases because they are injurious, odoriterous, andobjectionable.

It is particularly desirable to treat air discharged i'rom meatpackinghouses, where the waste material from butchered anlmals is treated iorcommercial disposal, because the air be- "comes contaminated withobjectionable odors.

Much progress has been made in the abatement of the more serious of the.stenches which were emitted. In this manner, one or the principalsources of atmosphere contamination is-removed to a great extent. Someof the fixed gaseous odors, however, still escape from the renderingapparatus into'theisurrounding room. Also, materials ofobjectionable-odor are still handled in open vessels, as when the oiIalis being macerated,

washed, and charged into the rendering kettles, and when the cookedmaterial is discharged from" the kettles. In this manner, the very largevolumesoi air which pass through. the work rooms become contaminatedwith a relatively small but oil'ensiv'e content of odorii'eroussubstances.

The use of closed vessels ion the more objectionable stench-producingoperations brought about so much improvement that, for a time, there wasa tendency to tolerate the less serious stenches still emitted. Assanitary standards have been raised, however, and, as residencedistricts have drawn closer to existing plants of this character, thenecessity for more complete stench abatement has become acute. No meanshas heretofore been available for this purpose, primarily becauseot thelarge volumes or air which must be deodorized to render a plantquiteunobjectionable.

.Inaccordance with the present invention, the substances are removedfrom the gases by contacting the latter with granular activated carbon.

,Although I do not wish to be limited thereto, I

preieroo employ the activated carbon materials of the apparatus now tobedescribed.

described in the U. S. patents to Newcomb K. Chaney No. 1,497,543 andNo. 1,497,544, both dated June 10, 1924, and I prefer to use the moreactive 01' the materials which are there described.

In order toprocess the large volumes of air discharged from ameatpacking plant in an apparatus of reasonable size, it is apparent thatthe air must flow through the deodcrizing apparatus at highveiocity. Toforce the air at high velocity through beds of granular carbon' requireshigh pressures and large expediture of power unless the carbon beds arevery thin. Thin carbon beds in conjunction with a high air velocityreduce the time of contact 01' the air with the carbon to a very smallinterval, and it was questionable whether, under economically Ieasibleconditions, theair wouldbe sufliciently deodorized. In this connectionthe low concentration of odoriferous substances in the air entering thepurifying apparatus is less significant than the much lowerconcentration of residual odors which must be attained in the airleaving the apparatus. The concentrations of the substances dealt withare infinitesimal as compared with the concentrations of gasoline,solvent vapors and other materials remaining in gases. after they havebeen passed through activated carbon 'in prior processes. Even whereactivated carbon is used in gasmasks, the velocity of the air throughthe carbon does not approach that necessary in the deodorization of theair from certain sections of meat packing houses. Nevertheless, I havebeen able to completely deodorize contaminated air from packing houseswith-great success by; the use i Reference is to be made to theaccompanying drawing in which the single figure is a top view or fasuitable odor-removing apparatus with one end cut awayto show theinterior construction.

In this drawing I show-an enclosed vessel, such as a steel tank I, theinterior of which is divided into a number of compartments solely bythin vertical layers 2 of activated carbon held in place by any suitablemeans, such as perforated metal plates. screens, or permeable materialin sheetlike form, a face of each bed being exposed to the face oi anadjacent bed. The odor-laden air is passed by a' suitable blower intothe air duct 3 and thence through the inlet valves 4 into the interiorof the tank. The outlet valves 5 on the opposite side of the tankare soarranged with reference to the inlet valves that all of the air mustpass through one or more layers oi activated carbon before it isflnallyreleased tothe atnosphere. Preferably the air passes through but onelayer of carbon. Suitable openings 6 are provided on the top and bottomof each of the carbon containers for charging and discharging asdesired.

After the carbon has been in service for several months and itsdeodorizing power has become nearly exhausted, one bed of carbon at atime may be removed from the tank and revivified. During this time thenecessary valves leading to and from the proper section of the tankareclosed so that no odor-laden air can escape to the atmosphere. After onebatch of carbon has been revivified it is again placed in the tank andanother batch is removed for reviviflcation. so that the continuousoperation of the deodorizingprocess is not hindered. A satisfactorymethod of revivifying the carbon is to heat it with steam to atemperature of about 300 C. If objectionable materials are driven out ofthe carbon by the steam, they may be partially condensed and passed'withthe water condensate into the sewer or burned.

The particular location of the apparatus in the plant is a matter ofconvenience, but it is advisable to place it so that the carbon mayberemoved when necessary for revivifying with the least possible effort.The discharge holes for the respective beds are so arranged that thecarbon may be passed from the vertical containers by gravity directlyinto the revivifying tank, or onto a suitable conveyor for transferringit to said tank; The apparatus of my invention may of course be used inconjunction with other odor abatement apparatus. For example, in caseswhere spray chambers are already in use, my apparatus may be used inseries with it, and the exhaust air from the spray chamber passeddirectly' into contact with the carbon where the deodorizing operationis completed. By previously sprayingtthe air with water it appears thatammonia, dust, and possibly some of the volatile odoriferous compoundsare removed and the active life of the carbon may thus be considerablyprolonged. v

While convenient for some purposes, it is not absolutely necessary toenclose the carbon beds in a metal container, since the main object ofthe apparatus is to insure passage of the odorladen air through theactivated carbon. For instance, the thin vertical beds of cabon may beplaced in a brick chamber or an ordinary room and all of the air fromthe work rooms passed into this chamber or treating room, and thence bysuitable dampers through the layers of activated carbon and into theatmosphere.

In determining the amount of activated carbon necessary for completelyremoving sub stances from a gas, such as in the deodorizing of air,consideration must be given to the volume of gas which it is necessaryto treat per minute with a view to the fact that the thickness and areaof the carbon bed will determine the power required to force the gasthrough it. I have found thatwith beds varying from 4 to 8 inches inthickness air may be passed through the beds at a linear velocity of to100 feet per minute withoutexcessive pressure, and with complete removalof the substances.

In a particular application of the present in- The thickness of thecarbon bed which.

the bed for eflfective removal of odors is approximately50 feet perminute. In order to obtain this velocity 9. total carbon bed area ofabout 600 square feet must be provided. With this total area dividedinto smaller beds and arranged as 5 already described, the pressure dropthrough the activated carbon will be approximately equivalent to 3inches of water.

The ability of activated carbon to adsorb various gases, vapors andother substances is well 10 known, but under the conditions as describedI believe that the actual adsorptive power of the carbon is not entirelyresponsible for the results obtained. It has been observed and isdisclosed in the patents and literature that activated car- 15 bon actsas a catalyst in certain reactions, and the ease 'with which manyodoriferous compounds may be oxidized has long been recognized.

I therefore believe that the remarkable efilciency of the carbon for thepurpose in question, in 2 which the conditions for adsorption aredecidedly unfavorable, may be attributed in some cases in part to itscatalytic action by which the odoriferous material is actually oxidizedand destroyed.

So far as I am aware my apparatus is the first 25 to be designed to meetthe combination of requirements which includes the treatment of verylarge volumes of gas. in inexpensive equipment, a small expenditure ofpower, and substantially complete removal of a volatile impurity fromthe 30 gas. For such'purposes a bed of granular carbon of a thicknesssmall in comparison with its area, and sufliciently small to permit thepassage of gas .with a velocity of at least 50 feet per minute under apressure equivalent to 3 inches of, water 35 has unique advantages. aWhile I have described my invention as being particularly adaptable foruse in meat packing houses, it is to be understood that with slightmodifications the same apparatus can be used 40 for practically any odorabatement purposes re- Y acter described comprising a tank, the interior50 of which is separated into a plurality of compartments by means ofthin vertical beds of activated carbon arranged in spaced relationtherein, inlet valves forthe air to be treated connected with alternatecompartments, the air admitted into the alternate compartments dividingand flowing through adjacent beds of carbon, outlet valves connectedwiththe remaining compartments, and means provided for individually chargingand discharging each of said carbon beds by gravity. 2. In a system forpreventing the dissemination of odors in large volumes of air; thecombination of a container, a plurality of thin vertical beds ofactivated carbon arranged in spaced relation I opposite side thereof,said valves being connected to the compartments in a manner whereby theair admitted into alternate compartments divides and flows throughadjacent beds of carbon before being released to the atmosphere, andmeans provided for individually charging and, discharging each carbonbed by gravity.

3. Apparatus for removingan odoriterous substance from air comprising acontainer, a pinrality of thin vertical beds of activated carbonarranged in spaced relation in said container with a face of each bedexposed to the face of an adjacent bed, means for admitting aircontaining the substance into alternate spaces formed between saidcarbon beds, the air admitted into the alternate spaces dividing andflowing through adjacent beds of carbon, means for discharging air fromthe spaces between those spaces into which air is admitted, and meansprovided for individually charging and discharging each of said carbonbeds by gravity.

4. Apparatus for removing odoriierous subinto the inlet chambers, theair admitted to such inlet chambers dividing and flowing throughadjacent carbon beds, means for discharging deodorized air from theoutlet chambers, and means provided for individually charging anddischarging each of said carbon beds by gravity.

ARTHUR B. RAY.

